Rangeomorphs

So you are stuck in the same place, but connected to your nearest and dearest via an all important filament which ties everyone together?  This might feel strange, but it is actually an exceedingly ancient arrangement.  Consider the lives of rangeomorphs, an ancient sessile marine animal which lived PRIOR to the Cambrian era, about 550 million years ago.  Many of the fundamental categories of multicellular life which are familiar to us originated in the Cambrian.  The rangeomorphs lived before that time…so it is a bit difficult to pin down their taxonomy.  Paleontologists have suggested that they are related to various groups of living suspension feeders and protists, but all of these attempts to pin down their exact place in the tree of life have been rejected.  Rangeomorphs lived during the last 30 million years of the Ediacaran Period (which was 635-542 million years ago) before the great phyla of life emerged.  Perhaps they were an extinct stem group somewhere between animals and fungi (!).

At any rate, even if rangeomorphs were their own weird kingdom of life, they were roughly analogous in form to many to many soft corals, glass sponges, ferns, luungworts and what have you.  They were mouthless (!) animals with no clear internal organs.  Their bodies consisted of many branching fronds a centimeter or so long.  They had no reproductive organs.

If you have been grinding your teeth wondering why I am writing about some blobby fronds which lived on the ocean bottom a half a billion years ago, you should open your mind.  There are some compelling questions here already.  If rangeomorphs had no mouths or organs how did they eat or sustain themselves?  They certainly were not photosynthetic.  How did they reproduce without reproductive organs?  Were they purely asexual?  We don’t know…However thanks to an exceedingly well-preserved bed of fossils just discovered in Newfoundland, we now know that rangeomorphs also had filaments which ranged in length from 2 centimeters (.75 inches) to 4 meters (12 feet) in length.  With these filaments the rangeomorphs (which formed vast monoculture colonies at the sea bottom) could conceivably communicate, transport nutrients, or even bud (as seen in the ‘suckering’ of plants like the infernal tree of heaven).  Maybe rangeomorphs were even subtly like syphonophorae–colony animals where different individuals (zooids) perform different functions in the manner of organs.

Not only is it interesting to speculate about the first great “forests” or “reefs” of life (assuming you don’t assign that role to the stromatolites of 3.5 billion years ago), it is also worth thinking about how different and alien the basal forms of life at the bottom of the animal “trunk” really were (assuming these guys were even animals).  I imagine them as colorful gardens of fleshy creatures not unlike seapens swaying in the currents of the ancient ocean, yet all strangely operating together like a clonal colony (which they almost certainly were–since how else would they come into existence?).  It forms a soothing mental picture during these tumultuous times.

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